Instrumentation & Measurement, Sensor Network and Automation (IMSNA), 2012 , 65 - 70, China 10.1109/MSNA.2012.6324517, 2012 International Symposium IEEE Performance Evaluation and Compression of Some Actuators and Sensors Piezoelectric Elements Arshed Abdulhamed Mohammed and Sallehuddin Mohamed Haris and Mohd Zaki Nuawi Department of Mechanical and Materials Engineering Faculty of Engineering & Built Environment Universiti Kebangsaan Malaysia, UKM 43600 UKM Bangi Selangor Darul Ehsan, Malaysia Email: [Arshed] arshad_ald@yahoo.com Abstract— This paper describes three types of piezoelectric structures that can be used as an actuator and as a sensor. These types are the Bender Element, the Plate Transducer and the Trigger-Accelerometer. Variations in usage, the internal structure and the direction of polarization are explained in order to understand the differences between the types and the responses of the piezoelectric structures. Among the many methods that are used for analyzing and building the transfer function of piezoelectric structures, the lumped parameter model was chosen as the method of analysis. This method proved very active in analyzing the effects of the internal parameters such as the dimensions of the piezoelectric structure and the elastic constant for the output response. In addition, after the transfer functions of the actuator and the sensor were built, the effect of the input signal types to the actuator and the sensor, such as the sine wave and pulse were analyzed. Finally, the results that were obtained, were compared with other previous works, and the results were very close. Keywords- piezoelectric; equivalent circuit; sensor; actuato; polarizatio. I. INTRODUCTION Today, sensors and actuators, especially piezoelectric transducers, are regarded as very common in mechatronics applications. Piezoelectric materials are polarized ceramic materials with the ability to produce electrical voltage if a variable load is applied onto it; it can also produce vibrations if an electric field is applied to it. Therefore, much research that has been published discusses its uses, properties and equivalent circuits; examples of using piezoelectric materials as actuators are the focus adjustment for VCR cameras [1], shutter drives for cameras, ink-jet printers [2], and Braille cells, while the applications that used the piezoelectric materials as sensors are ultrasonic sensors, molded underwater transducers, and motion sensors. Some real piezoelectric applications combine sensing and actuation like sonar applications. There are several types of piezoelectric ceramic materials such as Barium Titanate, Lead Zirconate Titanate, and Lead Titanate that are employed as actuators and sensors at the same time, but there are instructions from piezoelectric manufacturing companies [3] that recommend using some of these materials as actuators, like Lead Zirconate Titanate (P-7 and P-7B), and using Barium Titanate (P-3) as a sensor (fish finder sensor). This research interested in the differences in using piezoelectric as a sensor and as an actuator and focuses on the methods of use, internal structures, and equivalent circuits for the structures. II. SOME DIFFERENCES IN THE USE AND STRUCTURE OF PIEZOELECTRIC ACTUATORS AND SENSORS In actuality, there are many types of piezoelectric devices in our daily lives, but this research studied just three types of devices to explain the difference in structure and style of polarization between the actuator and the sensor (receiver):  The first type is the Bender Element (BE): it is shaped like a cantilever beam and contains two layers of piezoelectric ceramic sheets with a nickel shim in the middle (between the two layers of piezoelectric). Each layer is covered by a nickel electrode as shown in Figure 1. If the poling direction of these two layers of piezoelectric elements is in the same direction, it would be called parallel. And if the poling direction is in opposite directions, it would be called series. The parallel type needs low voltage to work, but the series type needs, for the same application, twice the voltage magnitude to work. The parallel BE is used as an actuator and the series type is used as a receiver[4] [5].  Plate transducer (PT): its name describes its shape. It contains a flat sheet of piezoelectric ceramic material sandwiched by two thin electrode layers from the outside. The P type (PT-P) is a primary type of plate transducer where it can produce a P-wave if the polarization direction is perpendicular to the electrode. The second type is the S type (PT-S) where it is clear from its name, it has the ability to produce an S wave, but the direction of polarization is parallel to the electrode surface as shown in Figure 2. Therefore, it is often used as an actuator and as a sensor [6]. Figure 1. Schematic representation of the Bender Element